Method for selling, protecting, and redistributing digital goods

ABSTRACT

This is a method for limiting access to selected features of a freely distributed multimedia file, by disabling selected features of the file (using encryption, compression, or other access denial), distributing the file with some enabled features as an inducement to new users, and offering to enable more features when a new user attempts to use a disabled feature. A licensing system then receives a request from the user&#39;s system, identifying a specific operating context and one or more features desired by the corresponding user. Accounting is done and an authorization is sent to the user or the user&#39;s system to enable the features. However, the authorization is uniquely associated with the measured operating context of the user and the features remain enabled only for said operating context, thus limiting full operation to authorized users, while permitting new users access to limited operations.

This is a Continuation in Part based upon pending application U.S. Ser.No. 09/764,293, which was filed on Jan. 19, 2001, which was aContinuation of U.S. Ser. No. 08/631,411, filed on Apr. 12, 1996, nowissued as U.S. Pat. No. 6,266,654, which was a Continuation in Part ofU.S. Ser. No. 07/990,455, filed on Dec. 15, 1992, now issued on Apr. 16,1996 as U.S. Pat. No. 5,509,070.

BACKGROUND—FIELD OF THE INVENTION

This invention relates to a method of encouraging distribution,registration, and purchase of freely copyable software and other digitalinformation. The invention applies to software as well as otherinformation which can be repeatedly copied with little loss of fidelity,and which is expressed via a hardware- or software-programmableapparatus, such as a computer or a digital audio tape player.

The Copyability of Software—Problem and Opportunity.

Digitally encoded information (“software”) is one of the mosteconomically important commodities of the era. The ease and economy withwhich perfect copies can be made, copied and distributed has promotedthe spread of software and related technologies through “traditional”commercial channels (retail and mail order sales, etc.) and through“non-traditional” distribution channels: computer user groups,user-to-user copying and sharing (e.g., of software and of music andvideo tapes), digital data networks such as the internet, CompuServe,static media such as CD-ROM disks loaded with large quantities of data,public libraries, and broadcast media. These non-traditionaldistribution channels in particular have made it difficult for softwarecreators and copyright holders to regulate the use of their creations,or to receive payment and registration information from their users.Consequently, software producers forfeit substantial revenues andvaluable information about their customer base and potential markets,while businesses and universities find themselves subject to legalprosecution and intimidation for software piracy.

Two approaches to these problems are copy-deterrence, andcopy-encouragement. Copy-deterrence is implemented through laws, licenseagreements and copy-protection technologies. Copy-encouragement ispracticed by “shareware” and small scale marketers who tolerate the lowregistration rates in order to reach the many potential users who can bereached at little cost through non-traditional distribution channels.Separately and in combination, however, these approaches have hadsignificant disadvantages.

Copy-deterrence.

Legal copy-deterrence techniques such as licensing agreements, andlitigation against companies and universities whose members knowingly orunknowingly engage in piracy are inefficient, expensive, and oftenunsuccessful. They incidentally create large numbers of “softwarecriminals” or “pirates” who routinely violate these unenforceable,hard-to-understand, and often unreasonable contracts.

Hardware and software copy-deterrence technologies have also beendeveloped, but they often raise the price and complexity of the softwareproduct, and inspire the development, sale and use ofcounter-technologies intended to defeat these copy-protectiontechnologies. Copy-protection techniques often inconvenience Users whohave legitimate needs and good reasons for making copies, and Userprotests against such inconveniences have in fact caused many softwarevendors to abandon copy-protection schemes. Yet another disadvantage ofhardware-based copy-protection techniques, as well as those whichinvolve modification or customization of the executable program itselfis that they prevent software vendors from exploiting the remarkablenon-traditional distribution networks which have sprung up in thesoftware marketplace, and which have given rise to the alternativeapproach, copy-encouragement.

Copy-encouragement

Shareware programmers and vendors encourage their users to copy, share,and distribute software to others in hopes that an adequate proportionof recipients will voluntarily contact the vendors, register themselves,and pay for the software which they are using. Only a small fraction ofusers actually oblige, but the non-traditional distribution channelsreach so many potential customers so cheaply, that the sharewarestrategy has been adopted by small-scale vendors who do not have theresources for traditional manufacturing, advertising, packaging, anddistribution methods.

In addition to the explicitly-shareware oriented software vendors, ithas been observed that many purveyors of popular software packagesactually tolerate a large amount of illicit copying in the hopes thatusers will eventually purchase a copy or an upgrade. In any case, it isobviously and crucially desirable to the vendors of easily-copyablesoftware that users register and pay for software.

Users of freely copyable software are often encouraged to register andpay for software by offering them additional benefits including“enhanced” versions of the software. But this strategy is deficient:withholding such benefits reduces the attractiveness of the product topotential users, and reduces the probability that users will recommendor give the program to other paying customers. And once a user haspurchased one enhanced copy, he or she has even less incentive forregistering additional copies to be used on additional machines, and isnow able to pirate the more powerful program, thus undercuttingincentives for registration among future users who might receive copies.There is a need for a means of INSTANTLY rewarding Users who registerand pay for freely copyable software, without undercutting futureincentives for registering, copying, and distributing additional copies.

Another problem with the prior art is that the people who actuallycreate software (i.e., programmers) often do not have the financialresources, business experience, time or motivation required forregistering, billing, and collecting money from paying users. This iswhy they often license their programs to established publishers andsettle for a small percentage of the profits which arise from the saleof their creations. Programmers would benefit greatly if they could“program a business operation” into their software just as they can now“program a computational operation” into their software—i.e., by addinga few lines of code which activate other routines which will do theirbidding. The present invention provides a means of satisfying thisunrecognized need in the industry.

Objects of the Present Invention

One object of the present invention is to encourage users to pay for,and register the freely-copyable software they actually use.

Another object is to enable programmers to “program a businessoperation” by writing a few lines of code, and thus reduce theirfinancial and other dependence upon software publishers, distributors,and vendors.

Another object is to allow programmers to be confident that theirlicensed representatives (software distributors and vendors) are in factreporting and paying royalties on all product sales.

Another object is to encourage and allow users to evaluate and exploituseful software before deciding whether to purchase, and to provide aconvenient and rapid way for them to purchase access to advancedfeatures severally or individually, as they and the programmer choose.

Another object is to incent users to distribute freely-copyable softwareto other people who would benefit from, and possibly purchase thesoftware.

Another object is to create economic and pragmatic incentives whichdeter piracy: the idea is that if higher registration rates could beattained, software prices could more accurately reflect their actualutility to the average user. This would reduce the incentives for piracyand associated technologies.

Another object is to increase the availability and profitability offreely copyable software and of the grassroots distribution channels.

Another object is to enable users to gain instant access to advancedfeatures of freely copyable software with minimal delay throughvirtually any form of communication technology with or without auxiliarytelecommunications equipment such as modem.

Another object is to eliminate the need for costly and inconvenientnon-copy-able adjuncts to software programs (such as expensively printedmanuals and packaging, hardware locks) etc., whose only purpose is todeter illegal copying of software and whose effect is to inflatesoftware prices.

Another object is to improve upon the technology embedded in theauthor's prior art (TAU) so that technology can be made available toother programmers as freely-copyable software tools.

Still further objects and advantages of the present invention willbecome apparent from a consideration of the ensuing description anddrawings.

SUMMARY DESCRIPTION OF THE INVENTION

Some of the above objects have been partially realized in a computerprogram developed for different purposes by the present author in 1989.This is probably the most relevant prior art, and the present inventionis both an improvement and a new use of the author's earlier invention,and of other related inventions, such as U.S. Pat. Nos. 4,796,220 and5,113,118.

My previously-developed program (“TAU” for the scientific analysis ofbiological rhythms data) is not copy-protected, and copying isencouraged. However certain “advanced features” of the program areinaccessible on a given machine until a unique, or nearly-uniquepassword is installed on that machine. These advanced features (such asthe ability to make publication-quality reports) are inessential foreducational and evaluation purposes (and so they do not discouragedistribution along the grassroots channel), but they are desirable forserious or professional use (and so they do encourage userregistration). The instant the password is installed, the “advancedfeatures” of the program are unlocked. The password, like the programitself, is freely-copyable (so backups can be made and restored freelyon the machine for which that password is appropriate). However, sincethe password is useless on other machines to which copies might betransferred, a new password must be purchased for each new machine onwhich the advanced features are desired. Thus the method encourages allusers to evaluate, copy, and distribute the software to other machinesand other potential users, while at the same time encouraging serioususers to register and pay for not-merely-evaluative use.

During two years of experimental monitoring, some deficiencies of thismethod were identified. While the method did ensure that the softwarevendor would report and pay royalties to the author (who was the onlyparty with the routine for generate appropriate passwords) the processby which the user obtained a password proved inconvenient for vendor,author, and customer. The protocol for obtaining passwords was: Programpresents ID to User, User gives ID to Vendor (by phone, mail or fax),Vendor gives ID to Author (by phone), Author gives Password to Vendor(by phone), the Vendor gives ID to User, User gives ID to program (viathe keyboard), the program installs the ID. The present inventionpreserves the security advantages while simplifying and making moreflexible the process by which passwords are obtained. A seconddeficiency was that while the method allows selective locking ofparticular features in an otherwise functional program, it became clearthat we needed a method by which Users could selectively purchase onlythose advanced features which were required on a particular machine. Athird deficiency was that when users upgraded or repaired theircomputers over the course of the experimental period, we had to issuereplacement passwords at no charge, and had no convenient means ofverifying claims about computer modifications. During testing it becameclear that if such deficiencies could be addressed, and if the schemecould be disembedded from the particular biological rhythms program forwhich it had been developed, it could be of quite general utility. Thepresent invention addresses these deficiencies, generalizes the schemetested in the author's earlier creation, and disembeds it from thatexperimental context in such a way that it can be incorporated intoother programmer's and software producers creations.

OVERVIEW OF THE INVENTION

The invention as described is most easily understood as a set ofsoftware tools which computer programmers can incorporate into their ownprograms by adding a few lines of code. These programmer-written linesactivate the software tools which enable or perform some or all of thefunctions to be described. However, it should be understood that thescope of the present invention is not restricted to the distribution ofexecutable software such as computer programs per Se. For example, theinvention could just as easily apply to a freely-copyable audio tapewhich would play at full fidelity only on an audio processor which wasprogrammed to require a valid password. Thus, the protected software andthe programmer's program might be separate entities with the latterintegrated into firmware, the protected software and the programmer'sprogram might be integrated with each other as in the case of my programTAU, and so on.

FIG. 1 illustrates the physical entities, processes, and functionscomprise the present invention.

The User acquires freely-copyable software through the “Laissez FaireDistribution Channel” 10 which comprises all of the methods previouslydescribed as non-traditional distribution channels as well as otherdistribution methods which might be developed in order to exploit thepresent invention. The “User's Processor” 15 is the device (typically acomputer, or digital signal processing device) which processes “theProtected Software” under the control of the “Programmer's Program” 20,and the Licensing Processor 90 under the control of the LicensingProgram 85, generates passwords for one or more Programmer's Programsand may also transact financial other transactions with the User. TheAuthorization Channel 80 will often consist of a 2-waytelecommunications channel such as a telephone line, and participates inthe transmission of IDs, Passwords and other information between theUser's Processor and the Licensing Processor.

When a Valid Password is Already Present.

We first describe the processes which occur when a User executes theProtected Software in the presence of a previously-installed validpassword. When the Programmer's Program 20 is loaded and executed on theUser's Processor, one of its component processes is to “Generate aPassword-able ID” 25 based in part upon the adequately-uniquecharacteristics of an ID-Target. The ID-Target 30 is the entity to whichaccess to the Software's advanced features is linked. In the figure, itis supposed that the ID-Target is the User's voice, but in otherembodiments it might be the serial number or other distinct features ofthe User's processor. (Prior art methods by which ID-targets such asvoices might be characterized for the production of Target-IDs will bediscussed below.) Once a Passwordable ID is generated, the Programmer'sProgram looks in an information storage location for a “PreviouslyInstalled Password 40. In a computer, the information storage locationwould typically be a file on a hard disk drive, but in principle thePassword could be installed in any location accessible by theProgrammer's Program, including the memory of the User interacting withhis or her Processor. The Programmer's Program then conducts a Check 45to determines whether the Previously Installed Password (if any) is thecorrect match for the specific Password-able ID which has beengenerated. If the password is valid the Programmer's Program Unlocks theAdvanced Features of the Software, and gives the User full and unimpededaccess to the program's advanced features (End State 50).

No Valid Password

If Check 45 does not find a Valid Password, the Programmer's Programgives the User the information he or she needs in order to decidewhether to a password for the Software's still-locked Advanced Features.Given this Offer 55, it is up to the User to decide whether or not toObtain a Valid Password (60) and communicate that decision to theProgrammer's program. If the User decides not to obtain a validpassword, the program simply leaves the advanced features Locked (EndState 70).

User Decides to Obtain a Valid Password

However, if the User's Decision 60 is to obtain a valid password, anAuthorization channel 80 must be activated which establishescommunication between the User (or his processor) and the Licensingsystem which is comprised of Licensing Processor 85 executing LicensingSoftware 90. The function of the Authorization Channel 80 is to send thePasswordable ID, and typically other payment information as well, fromthe Programmer's Program to the Licensing system and then to transmit avalid Password from the Licensing System to the Programmer's Program.The functions of the Licensing system is typically to receive paymentinformation from the User, arrange for the transfer of funds from theUser to the Programmer, and generate and transmit the specific passwordrequired by the Passwordable ID. Upon receipt of the password theProgrammer's program unlocks the advanced features of the program justas in Step 50, and also installs the Password in storage location 40 sothat on subsequent executions of the Programmer's program the flow ofcontrol will terminate at End State 120, (identical to end state 50)with Advanced Features Unlocked.

Punchline

Note that if a copy of the now-Unlocked software is copied to anotherID-target it will automatically relock, provided either that the newtarget-ID is different from the old target-ID, and/or that the Passwordfor the original ID-target was installed in such a way that it could notbe transferred to the new ID-target.

DETAILED EXPLICATION OF THE INVENTION

The Laissez Faire Distribution Channel

The present invention differs from earlier inventions in separating thedistribution channel by which software is acquired and distributed fromthe authorization channel by which licensing is transacted. Oneadvantage of this innovation is that it allows Users and softwaredistributors to support rather than impede the flow of informationthrough the Laissez Faire Distribution channel which develops relativelyspontaneously and at little cost to participants when freely-copyablesoftware is present. Another advantage is that relatively littleinformation needs to flow through the proprietary authorization channel.The present invention may well expand the Laissez Faire Distributionchannel by making it economically viable for Software publishers todistribute software through the mail, as give-away items tucked into thevolumes of third-party books, or as donations to public libraries, andso on. Note however, that while the Laissez Faire Distribution Channelmay thus support and be supported by the present invention, it is not anecessary part of the present invention. The present invention couldalso support the distribution, by mail and other means, of non-copyablesoftware (e.g., on CDROMs), provided only that access to advancedfeatures can be locked in the absence of a valid password on the User'sSystem.

The User's System

The nature of the User's Processor and the Programmer's Program willdepend on the nature of the Protected Software being processed. Theprocessor for a protected computer program or a protected text file istypically a traditional computer; the processor for a protectedaudio-tape is a tape player, and so on. In essence then the User'sprocessor is a device which processes the protected software undercontrol of the Programmer's Program. Several observations are pertinent.First as multi-media processors are developed they will be able to dealwith more and more kinds of protected software in an integrated fashion,so the scope of the present invention should be increasingly broad.Second, the Programmer's Program need not necessarily be distributed ordistributable through the Laissez Faire Distribution Channel. It couldtherefore be incorporated into the hardware, firmware, or software ofthe User's Processor. Thus, to the extent that the User's Processor hasbeen made to mediate the methods of the present invention, it isintended that it be covered by this patent.

Generate Passwordable-ID

The Passwordable ID is the adequately unique string of symbols for whicha specific password is required. The oxymoron “adequately-unique” isused because (1) adequate utility may be achieved even if PasswordableIDs are just variegated enough to significantly reduce the probabilitythat a password obtained for one ID-target will work for anotherID-target to which the first password might be transferred, and (2)because the need for one-of-a-kind uniqueness can be further reduced ifpasswords are installed (in step 100) in such a way that they are nottransferrable from one ID-target to another.

The ID must be generated in such a way that two ID-Targets will generatedifferent IDs. Also, in order that a plurality of Licensed-features in aplurality of software programs be independently licensable on the sameID-Target, any two Licensed features must be able to generate differentIDs even in conjunction with a single ID-Target. Those familiar with theart will recognize that this can be achieved a variety of ways. In onepreferred embodiment, each item of protected software is assigned anadequately unique P-digit Program ID, and each licensed Feature isassigned an F-digit Feature-ID, and each ID-Target can be associatedwith a T-digit Target-ID such as a serial number. Once assigned (usingmethods described below) these ID numbers are combined in a fashionwhich preserves their uniqueness (e.g., by concatenating them to producea number with N+M+T digits capable encoding 10^^((N+M+T)) values) andthen using this combination, an encryption of it, or some otheradequately-unique transform of it, as the ID.

In addition, to ensure error-checking when the Passwordable ID istransmitted to the central computer (80), it is desirable that aPasswordable ID satisfy some kind of coherence constraint such that themis-report of a single digit can be detected. One coherence constraintwould be to append two more digits to the ID which would constitute achecksum for the preceding digits. Thus an error would be detected whenthe checksum and the preceding digits were inconsistent.

Other information could usefully be encrypted into the ID as well. Forexample, to facilitate compensation of the software creator and toensure that the correct price is being assessed for a given Password(Step 95), the ID could also encrypt the price of the software and thename of the party who should receive royalties, and so on.

Thus the invention requires only that an adequately unique ID begenerated; it does not require that the ID be generated any particularway, and our invention should not be considered to be dependent on anyparticular method. As illustrated in the next paragraphs, a variety ofmethods-can be adopted by individual programmers to suit the needs oftheir application.

Method of Assigning Feature-IDs and Program IDs

To the extent that a sufficiently large number of digits have beenallocated Feature and Program IDs, the programmer can safely use arandomly-seeded number generator to select values for these IDs, sincethe probability that two programmers would fall upon the same numbers isadequately small. Alternatively, unpredictable Feature-IDs can beassigned by a central computer maintained by operator the LicensingSystem, which computer maintains a database of previously assigned IDs.

Method of Assigning Target-IDs

The method of assigning target-IDs will depend upon the nature of theID-Target device, the requirements of the Programmer's program, and theintended distribution. It should be noted that target-IDs need not begenuinely unique for the present invention to be of substantial utility:it is sufficient that they be rare enough to substantially reduce theprobability that the ID assigned to one ID-Target will not also beassigned to one of the ID-Targets to which the software might be copied.Furthermore, to the extent that adequately rare Target-IDs cannot beassigned, the objectives of the invention can still be achieved byrendering the installed password non-copyable using conventionalcopy-protection techniques. Thus, the purpose of the next paragraph isto demonstrate that adequately unique IDs can be generated in a varietyof existing and anticipatable situations using currently-availabletechnology.

Those with ordinary skill in the art will recognize that many ID-Targetdevices possess unique identifiers which can be accessed by theProgrammer's Program and used as the basis for target-IDs. For example,many computers, printers, hard disks, and CD-ROM disks havesoftware-accessible serial numbers. Of those devices which do not haveserial numbers, many have software-assessable characteristics (such asthe number and kind of peripherals, central processing unit chips, theinterleave factor and timing characteristics of the hard drive, etc.)which can be used to generate a target-ID which is sufficiently uniqueto satisfy the needs of the situation. In addition, a variety ofcomputer devices have been invented for retrofitting a computer with aunique serial number, and these too could be used to generate target-IDson computers which were so-equipped.

Other kinds of ID-targets, such as the voice of the User can becharacterized using existing pattern-recognition technologies togenerate a user-specific target-ID which is “fuzzy enough” to recognizethe user under varying conditions, but specific enough to reject otherUsers.

In this paragraph we disclose a software-based method we have developedto retrofit Target-IDs with writeable non-volatile storage devices (suchas computer hard drives or programmable read-only-memory (PROM) chips.By this method, a nearly unique “tattoo” is generated and written to thestorage device. The near-uniqueness of the “tattoo” can be achieved byusing a random number generator initialized or “seeded” in a fashionwhich will vary from one ID-Target to the next (this facility istypically incorporated into a “randomize” command in many programminglanguages). Alternatively or equivalently, a nearly-unique ID can bebased upon a high-resolution time-stamp generated using the processor'ssystem clock, or by a variety of other means. To the extent that this“tattoo” is the only source of the Target-ID's uniqueness it isdesirable that it not be copyable from one ID-target to another. Thiscan be achieved by hiding the tattoo from the User, copy-protecting it,etc., using techniques known to those with ordinary skill in the priorart.

Once the Feature-, Program- and Target-IDs are assigned, thePasswordable ID which synthesizes them can be generated using methodslike those described above.

Check for Valid Password (step 45),

Generate Valid Password. (step 93)

Because the method of determining the validity of the password (step 45)depends upon the method by which passwords are generated (step 93) inthe Licensing Processor (90), these two processes will be describedtogether.

The User's Processor under control of the Programmer's Program checksfor a valid password by accessing the password storage location of step100, and determining the validity of any candidate passwords found inthat location. One password generating method uses the ID, or sometransform of it, as the seed to a deterministic number generator anduses the random number generator to generate a deterministic butunpredictable Password. In that case, the method by which theProgrammer's Program determines the validity of the password is: use thesame method to generate the Password in the User's processor, comparethe password generated to the candidate password, deem the candidatepassword valid if it is identical to the generated password.

An acceptable but undesirable feature of the method just described isthat the password-generating algorithm must be secreted inside theProgrammer's program where it might be discovered by hackers seeking tobreach the system. This shortcoming could be eliminated if theProgrammer's Program were capable of validating, but not generating, avalid password. One way this could be accomplished is to ensure that thelicensing system is substantially more powerful than the User's system.In this case, one could exploit the fact that prime factorizations oflarge numbers are easier to confirm than to generate by adopting theconvention that the password generated by the licensing system would bethe prime factorization of an N-digit number produced using the ID asrandomization key, where N is chosen to be within the factorizationcapabilities of the licensing computer but not the Users or hacker'scomputer. Under this password-generation method, the password-validationmethod (which would be within the capability of the User's computer) isto generate the N-digit number and confirm that it is indeed the productof the factorization contained in the password.

Another way which could ensure that the programmer's program couldvalidate but not generate a Password is to exploit the fact that, givena sequence of pseudo random numbers, and given a candidate-seed, it iseasy to confirm that the sequence is generatable from thecandidate-seed, but it is difficult to generate the seed from the pseudorandom number sequence alone, unless one also has a detailedunderstanding of the random-number generation algorithm and an algorithmfor reversing its operation. This fact could be exploited for thepresent invention by putting the random-number generating algorithm inthe Licensing program, while secreting the reverse-operation algorithmin the Licensing Program only. Then the Password for a givenPasswordable-ID could be the random number seed capable of generatingthat Passwordable-ID. Thus, the Licensing System would have thewherewithal to generate that Seed while the User System would only havethe ability to confirm it. To prevent hackers who had isolated therandom number algorithm in the Programmer's Program from using aniterative trial and error process to discover the Seed capable ofgenerating the Password-able ID, one could ensure that the random-numbergeneration algorithm requires so much computational power that, while itwould be fast enough to generate a particular sequence when providedwith a seed, it would be too awkward to be used to test all possibleseeds to find one which generates the particular sequence. [There arecitable patents and texts which explain random number-generationmethods]

Other methods to increase the security of the password validation methodcan be envisioned, and are intended to fall within the scope of thepresent invention.

Unlock Advanced Features

The result of the Password Validation method 45 must be made availableto the Programmer's Program. This can be achieved by providing theprogrammer with a function such as PasswordIsGood(ID,Password) whichreturns a value of true if the Password is valid, and false if not.Conventional programming techniques can then be used to unlock anAdvanced Feature if the function returns true. For example,

-   -   If PasswordIsGood(ID,Password)        -   then Enable_Advanced_Feature.            Offer Password

If PasswordIsGood returns false, this can similarly be used to triggerroutines which provide the User with instructions about how to obtain avalid password, and invite the user to do so. The nature of theseinstructions depends upon the Authorization Channel used in step 80, butminimally they must provide the User with the information required tomake an informed decision about whether or not to acquire a password.This might include information about the benefits of the AdvancedFeature and the costs of obtaining a password for that advanced feature.

User Decision: Obtain Valid Password?

It is thus the User's decision (step 60) whether to acquire a Passwordor not. If the User decides not to acquire a password, the AdvancedFeature in question remains locked.

Enable the User to Obtain a Password if Desired.

If the User elects to purchase a password to unlock an advanced featurehe or she can be given appropriate instructions, based upon theAuthorization procedure 63 and Authorization Channel 80 adopted by theprogrammer.

Minimally, the ID must be transmitted to the central computer. Inaddition, the software vendor may want to receive payment, and personalregistration information such as name, address telephone number,computer system, etc. All of this can be accomplished easily usingreadily available technology, with or without human assistance.

For example, the Licensing software could inform the User of the FeatureID for which a password is needed, and instruct the User to call aparticular telephone number and submit the ID via voice, touch-tonekeypad, etc . . . Payment for the password can be transacted by using a900 (toll call) telephone number, or by instructing the user to submit acredit card number, etc. Credit cards can be confirmed while the User ison the line, and during this time registration information can also beobtained over the phone, if desired. When the ID is received by theLicensing Computer, it is checked for internal consistency based uponthe methods of Step 25 to assure that there have been no communicationerrors during transmission of information from Licensing-processor tocentral computer. When consistency has been confirmed, and payment (ifany) transacted, voice-technology is used to give the User the password,to invite the User to repeat the password (for purposes of checking),and to correct the User if there has been any miscommunication of thepassword. Then Instruct the User to submit the password to the LicensingSoftware and to hang up the phone. And finally, arrange for theProgrammer to receive appropriate compensation; e.g., by transferringthe payment received from the User, minus a commission, to an accountdedicated to the programmer.

Alternatively, if the User's Processor can be put in directcommunication with the Licensing Processor, (e.g., if the LicensingProcessor is equipped with a modem), all of the User's decision,registration and payment information can be obtained off-line by theProgrammer's Program and then the two Processors could computer couldcommunicate rapidly and automatically with out any User involvement. Inthis case, the User need not be informed about the nature of the ID orPassword.

Alternatively, albeit much more slowly, communication with the centralcomputer could be conducted via paper mail with human intervention. Andso on. It will thus be understood that these are examples of preferredembodiments, and that other variations, improvements, etc. are intendedto fall within the scope of the present invention.

Transact Authorization

All of the transaction-authorization functions of the Licensing,Processor, under control of the Licensing Program, can be implementedusing commercially, available voice-processing and computer technology.Some or all of these functions could also be accomplished with humanintervention, e.g. by a telephone operator associated with the LicensingProcessor. Thus, it is the procedures described here which are theessential features of the present invention, not the specificimplementation.

Minimally the Licensing Processor (with or without human assistance)must receive the transmitted ID, generate the appropriate password usingmethods complementary to those of the Validation Procedure 45 asdiscussed previously, and transmit that password back over theauthorization channel.

Additionally, the Licensing Processor may be programmed to charge theUser for the Password in a manner consistent with the Password Offer ofStep 55, and credit the Programmer appropriately. If the AuthorizationChannel 80 is a 900 telephone number, debiting of the User is automatic;crediting the Programmer would be accomplished by updating a database ofpayments due, triggering a transfer of funds by communicating with abanking computer, etc. Alternatively, the Licensing Processor can beprogrammed to obtain and confirm the validity of a credit card orpurchase order number before providing the password, and so on.

Finally, the Licensing Processor may be programmed to obtainregistration information such as the User's name, address, telephonenumber, make and model of processor, etc. This information may be ofsuch value to the purveyor of the protected software (e.g., for purposesof advertising or follow-up sales) that it may be economically viable toaccept registration information in lieu of monetary payment. Thisinformation would then be stored in a conventional database to which theSoftware purveyor would have access.

Install the Valid Password.

Once received from the Licensing processor, the valid password must beinstalled in a non-volatile storage area such as a file on a hard diskso that on subsequent occasions when the licensing software is run onthe licensing processor, the correct password will be found and therelevant advanced feature will be unlocked (step 50).

To the extent that the Target IDs assigned in step 25 are notone-of-a-kind on each ID-Target, it is desirable that the installedpasswords be laid down in a fashion which renders them tamperproof andnon-copyable, using copy-protection technology of the prior art. Thatway, a new password will be required on a new ID-target, even if theUser uses a mass-copy operation to transfer all (copyable) filesassociated with the program to the new ID- Target, and even if thePasswordable ID in the context of the new Target-ID is identical to thatof the old ID-Target.

Unlock Advanced Features

Additionally, upon receipt of the valid password it will be convenientto unlock the Advanced Features of the program as in Step 50.

Exemplary Embodiments

In order to partially indicate the scope of the present invention, twoembodiments and applications consistent with the foregoing will now bedescribed.

The author's previous computer program, TAU, could be improved byadopting the present invention. The computer program would befreely-copyable and incorporate both the Protected Software and theProgrammer's Program. The Target-IDs would be distinguishing features ofthe User's Processor (e.g. a serial number in the CPU) and two AdvancedFeatures would be the ability to produce high quality printouts and theability to save modified data to disk. According to the methods of step25, the two Advanced Features would generate two Passwordable IDs whichare adequately specific to the User's Processor. The Programmer mightfind it convenient to adopt the convention of storing passwords forthese IDs on the Hard Drive of the User's Processor in files whose namesare identical to the IDs. If valid Passwords are determined to be absentduring Check 45, then whenever the User attempts to use the LockedFeatures, she would be invited to telephone the site of the LicensingComputer, and to give a human operator there the specific IDs requiredas well as a credit card number. If the User's Decision 60 is to obtaina password for high quality printouts, she telephones the humanoperator, provides the Passwordable-ID for that advanced feature as wellas credit card authorization information and receives in return thePassword for that ID. A utility incorporated into the computer programwould allow the User to type in any passwords obtained, then installpasswords, and unlock the appropriate advanced feature.

In another application and embodiment, it may be supposed that theProtected Software is encrypted in a freely-copyable text filecontaining information which is intended to be displayed on a computerscreen only in the presence of a particular authorized individual who isidentified on the basis of his vocal characteristics. In this case, theID-Target would be the User's voice, the Protected Software would be thetext file, and the User's Processor would include appropriate voicerecognition hardware and software (the latter software including theProgrammer's Program). So that a tape-recording of the User's voicecould not be used to thwart the present scheme, the feature ID would becomputed as follows: Each time it is desired to assess thecharacteristics of the User's voice, present a short random sequence ofletters and ask the User to read them aloud. Using prior-art voicerecognition technology (e.g., that which is already being marketed byvendors such as Dialogic Inc.) to confirm the sequence of letters spokenand generate a Target-ID which numerically encodes parameters whichdistinguish human voices. The password for this Target ID would be asequence of letters to be memorized by the User. If the sequence is thecorrect one, the appropriate Advanced Features of the encrypted text aredecrypted by the Programmer's Program; if the User does not present anappropriate Password, he is invited to obtain one as in the previousexample. Thus in this example, the User's own memory would be thestorage location for the Password.

Description of One Possible Software-tool Implementation.

One object of the present invention is to allow programmers toconveniently invoke the just-described methods by adding a relativelysmall number of lines of code to their own programs. This can beachieved by supplying programmers with a few simple commands whichinvoke more complex operations implemented in pre-compiled objectmodules or units. An exemplary implementation in the Pascal language isnow described with the understanding that other languages andapplications will require different implementations, and thatprogrammers may well want to augment or replace one or more of theseroutines with variants of their own, while remaining within the scope ofthe invention.

Function GetTargetID:longint; (step 30)

This is a function required for step 25, returning a number which isadequately specific to the ID-Target 30. Variant functions might beprovided which are more or less specific in order to suit the needs ofthe programmer, and in order to adjust the sensitivity the Target-ID tosmall changes in the characteristics of the ID-Target (for example, ifthe Target-ID is a User's voice, it might be desirable for the ID-Targetto remain constant when the User's voice is hoarse or stressed).

Function MakeID(GetTargetID, FeatureID,

-   -   ProgrammerID):Longint;

This function implements step 25. It generates the Passwordable ID basedupon the Target-ID (obtained from GetTargetID or by other means of theprogrammer's devising), upon a FeatureID (assigned by the programmer),and upon (in one preferred implementation) a ProgrammerID which encryptsthe identity of the Programmer who should receive royalties forpurchased passwords.

Function GetInstalledPassword:longint;

This function looks in a predetermined storage location 40 (e.g. in afile with a particular name, or a name based upon the ID itself) for acandidate password. If no Password is found, GetInstalledPassword gets adefault value such as 0. If a Password is found, GetInstalledPasswordreturns the value of that Password.

Function PasswordIsGood

(GetID, GetInstalledPassword):boolean;

This function implements step 45. If the InstalledPassword is valid forthe ID in question, GetPasswordValidity returns True; otherwise itreturns false. The Programmer's Program can use this value to decidewhether the advanced feature(s) should be unlocked or whether to Usershould be invited to obtain a valid password.

Function GetNewPassword:longint;

This routine demonstrates a way in which a programmer could invoke steps55, 60, 93, 95 through the use of a single function. One possibleimplementation of the routine, pseudo-code, follows.

-   Function GetNewPassword(GetID):Longint;-   begin-   writeln (‘Because the current password, is not valid you will not be    able save your document to disk.    -   A call to the licensing-computer's 900 number will cost you only        $1.00, and take only 30 seconds, and your password will remain        valid as long as you keep this computer.    -   Shall I use the modem on your computer to get you a password to        unlock this advanced feature? ’)-   if UserSaysYes then    -   Get_Modem_To_Get_Password_For_This (ID)        -   else    -   GetNewPassword:=0;-   end;    Procedure InstallNewPassword(NewPassword):

This procedure implements step 100. By installing the password in thestorage location which is searched by function GetInstalledPassword. Tothe extent that the Target-ID obtained in step 25 was not adequatelyunique, it may be desirable to use existing technology to Install thepassword in a hidden and copy-proof fashion. That way, even if multiplemachines require the same password, the password will have to beobtained on each such machine.

Example of Programmer's Program

Given the above, the Programmer can “program in” the computational andcommercial operations embodied in the present invention by using aboolean array called AdvancedFeatureIsLocked to determine whether theAdvancedFeature is to be executed or not each time the User tries toinvoke that AdvancedFeature.

-   An example would be-   if AdvancedFeatureisLocked[FeatureID]    -   then OfferPassword    -   else ExecuteAdvancedFeature(FeatureID)

Given the above, the Programmer need only execute the following lines atthe beginning of the program or any time it is desired to give the Useran opportunity to purchase a password.

-   If PasswordIsGood (MakeID(GetTargetId, FeatureID,    -   ProgramID), GetInstalledPassword)    -   then AdvancedFeatureUnLocked[FeatureID]:=False;    -   else begin        -   NewPassword:=GetNewPassword;        -   if NewPassword<>0 then begin            -   InstallNewPassword (NewPassword):            -   AdvancedFeatureIsLocked[FeatureId]:=False;        -   end:    -   end; {Password was not Good when first checked}        Extensions and Enhancements

The invention could be enhanced in a variety of ways which would make iteven more convenient for User and Programmer. The following disclosuresare offered as exemplary embodiments and extensions of the foregoingteachings, and should not be construed to limit the scope of the presentinventions.

Increasing Utility

Those with knowledge of the prior art and the teachings of this patentwill recognize that “package” Passwords could be offered which wouldunlock “suites” of advanced features at reduced cost or inconvenience tothe User. When the protected software is part of the Programmer'sProgram this could be easily implemented by the Programmer using newboolean variables (such as “Suite3IsUnlocked”); when the protectedsoftware is non-executable text, this could be easily implemented byencrypting a suite of narrow-scope passwords in a block of text whichcan only be decrypted using a higher-scope Suite-Password; and so on.

Increasing Security

The invention as described provides a substantial deterrent to thecasual piracy of protected software, but its utility does not requirethat it be immune to the concerted efforts of skilled hackers. Numerous“hacker-proofing” improvements can be imagined such as basing theuniqueness of the created “tattoo” upon the User's reaction time inresponse to some prompt rather than upon the system clock on theassumption that the former might be more controllable throughtechnological means.

Protecting Non-executable Data

As noted above, the Programmer's Program and the Protected Software neednot be identical, and neither need to be freely copyable in order tofall within the scope of the present invention. Nor must the ProtectedSoftware be executable code. In one embodiment, for example, both theProgrammer's Program and the Protected Software could be distributed onnon-copyable CDROMs, and the Programmer's Program could serve decryptdata stored in separate files on the CD-ROM. In this situation, and inother situations in which the Advanced Features in question areencrypted data, the function of the Programmer's Program is to provideaccess to the encrypted data if and only if a password is present whichis specific to the adequately-unique ID of the User's ID-Target (e.g.,the CD-ROM disk, or the CD-ROM player). One way that this could beaccomplished would be for the Programmer's program to contain the keyneeded to decrypt the encrypted data and to invoke that key only in thepresence of an appropriate password. However, in order to make it moredifficult for crackers to decrypt the encrypted data in the absence of avalid password, it would be preferable if the Programmer's Programsimply lacked the information the cracker requires. Several ways inwhich this could be achieved is disclosed in the next paragraphs, whichcan be considered an expanded explanation of the processes required toGenerate Passwords and Unlock Advanced Features.

Encrypt each Advanced Feature (e.g., a block of text) using a prior-artkeystream encryption technique based upon a pseudo-random keystreamgenerated by a pseudo-random number generator initialized with anarbitrary Encrypting seed. In this technique, successive pseudo-randomnumbers are used to transform in a reversible fashion the successivecharacters of a text-to-be-encrypted (e.g. by applying the XORoperation). Decryption involves the regeneration and application of thesame pseudo-random number to the encrypted data, and therefore requiresthat the Encrypting Seed be located in the Programmer's Program or inthe Encrypted text, where it might be discoverable by hackers.

However, using the following technique, the Encrypting/Decrypting Seedonly needs to exist transiently in the User's System. As illustrated inFIG. 2, the preliminary step 210 is to Encrypt each block of text to betreated as a single Advanced Feature with a different Encrypting Seed S,and assign a Feature ID to that text. A table associating eachEncrypting Seed with its corresponding Feature ID is provided to theLicensing System, but is not provided to the User's System. When theUser decides to obtain a Password, the Licensing computer is providedwith the Passwordable-ID and the Feature ID as in step 220. With thisinformation the Licensing System can execute step 230, using the FeatureID to access the Encryption Seed S for the Feature in question, andencrypting S using the Passwordable ID as an encrypting seed for a newpseudo-random keystream. The now-encrypted S is then treated as aPassword to be transmitted to, and installed on the User's system. Onceis possesses this password, the User's system can execute step 240:using its own Passwordable ID, it decrypts S, uses S to decrypt thetext, and then discards S. In this way, the decrypted S is onlytransiently present in the User's system, and is only accessible in theUser's system with the appropriate ID.

A variation of tile above scheme is more secure, but is only applicablewhen relatively large amounts of data can be transmitted to the User'ssystem (e.g. through a digital data link connecting the Licensing Systemto the User's system. In this variation, the text to which the Userseeks access is itself treated as the Password to be transmitted andstored on the User's System. Prior to transmittal, the Licensing systemencrypts the text using the User System's Passwordable ID as theencryption seed. The User's system will be able to use its own ID totranslate the “password” into the desired text, but other systems withdifferent IDs will not.

In the previous sections, it was assumed that the reader would view theprotectable non-executable data (called “text” for convenience only)using the Programmer's Program. However, it would be desirable if suchdata were accessible, in the presence of a valid password, tothird-party programs which had not been designed with the presentinvention in mind. This can be achieved by combining the presentinvention with prior art of the sort used in commercial software for“on-the-fly” file compression, such as SuperStor, and Stacker. Ascurrently .implemented, these “terminate and stay-resident” programsinterpose themselves between a computer's Disk-Operating System (DOS)and third-party application programs which obtain data from the DOS. Thecurrent function of these programs is to increase the storage capacityof rewritable storage media by transparently compressing the applicationprogram's disk output before passing the data on to the DOS, and todecompress data obtained from the DOS before passing it on to theapplication program. By incorporating the present teachings into thisprior art technology, new software could be developed which, in thepresence of the appropriate passwords, would decrypt data which hadpreviously been encrypted on the storage medium, and then pass thenormal-seeming decrypted data to third party application programs.

Network Environments

Another desirable feature of the present invention is its applicabilityto network environments. That is, in situations where multipleworkstations access files which are stored in a shared file directory,it might be advantageous if a single copy of the Protected Software aswell as all Passwords could be located in a central location whilepasswording was specific to each workstation. This could be accomplishedsimply by using the workstation as the ID-target, and by storingpasswords in workstation-specific locations, e.g., in files whose namesare based upon the Passwordable ID. For other programs, it might bedesirable if all workstations in a given network were covered by thesame server-specific license. This could be achieved simply by using thenetwork server as the ID-target. Other variations of this sort caneasily be envisioned and adapted to the needs of the programmer.

Hardware Changes.

A potential problem with the present scheme could arise which userschange the characteristics of their ID target. This might have to bedealt with on a case by case basis, but in standard cases, for whichstandard GetID functions might be provided, there is a solution which ishere disclosed. That is, invite users to call a customer serviceoperator for free replacement passwords if minor changes in theirID-Targets have led to changes in Target-IDs, and provide the freepassword provided that the User's description of the change can beconfirmed using the technique of the next paragraph.

In a non-volatile storage location of the User's Processor such as theUser's hard drive, store a “profile” which records an encrypted list ofthe N characteristics of the ID-target on which the Target-ID is based.Create or update this file whenever a valid password is encountered.Whenever an invalid password is encountered compare the values storedwithin the profile to the values of the Target-ID which has just beencomputed. In the latter case, construct an N bit word, giving each bit avalue (1 or 0) which indicates whether or not the Nth characteristic ofthe profile differs from the Nth characteristic responsible for theTarget ID. This N bit word, transformed or encrypted as desired, canthen be communicated to the Licensing System's Customer Service operatorwho determine which characteristics changed since the last time a validpassword was installed on the User's Processor. This determination canthen be used check the User's veracity, in order to decide whether tohonor the User's request for a replacement password.

Password Disks

Some Programmers or Software vendors may not wish to be bound to thesoftware, hardware, or customer support policies of the Licensing Systemor its managers. It would therefore be desirable to be able to provideSoftware vendors a means of generating passwords to their own products,but not the products of other vendors. From the point of view of thepurveyor of services based upon the present invention, it is alsodesirable that the number of passwords a vendor could generate belimited in a way which allows the purveyor to receive compensation inproportion to the number of Passwords the vendor generates. This can beachieved by providing Software vendors with modified versions of thelicensing programs on tamper-proof and copy-protected media. Themodifications would involve constraining the Licensing Program so thatit only generates Passwords for IDs based upon a particular Software IDassigned in advance to the vendor purchaser of the Password Disk. (Thisis easily accomplished using the present teachings when the PasswordableID encrypts the Software ID: then the Licensing Program can be made torefuse Passwordable-IDs which are based upon other Software IDs.) Priorart tamper-proofing and copy-protection technology available from suchvendors as Aztech Inc. of Arizona, can then be used to set the number oftimes the Licensing Program on the Password Disk can be executed. Inthis way Password Disks can be sold to vendors at prices arecommensurate with the numbers of Passwords to be generated, andpurchasers of such Password Disks can then implement their own licensingsystems and customer support policies

Additional Ramifications

Although the description above contains many specificities, these shouldnot be construed as limiting the scope of the invention but as merelyproviding illustrations of some of the presently preferred embodimentsof the invention. For example, other embodiments might involve differentID-Targets such as telephone numbers, node addresses in local area orwide area networks, visual appearances, biological characteristics oftissue samples, etc. In alternative embodiments, Password-generatingprocessors and/or Password-sensitive processors could include mechanicalcalculators, optical computers, etc., and Licensed software couldinclude video or multimedia information, non-digital but easily copyableinformation such as analog audio or video recordings, etc. Finally, thescope of the present invention is intended to include all distributionchannels to which it can be made applicable: for example, under thepresent scheme computer manufacturers could load large amounts ofcommercial software onto their products' hard disks and sell to users onan after-the-fact basis.

Thus the scope of the invention should be determined by the appendedclaims and their legal equivalents, rather than by the examples given.

1. A method for limiting access to selected features of a multimediafile, comprising the steps of: disabling selected features of saidmultimedia file; distributing said multimedia file with at least someenabled features; offering to enable one or more specific disabledfeatures when a user attempts to use at least one of said specificdisabled features; receiving a request from a user or user's system,said request identifying an operating context and identifying said oneor more disabled features; and transmitting an authorization to saiduser or user's system to enable said one or more disabled features,where said authorization is uniquely associated with said operatingcontext; whereby said selected features remain enabled only for saidoperating context.
 2. The method of claim 1 further comprising the stepof: identifying an operating context and a licensor from information insaid request and arranging to send an authorization according to anagreement between said user and said licensor.
 3. The method of claim 1further comprising the steps of: providing a user environment in whichpre-defined actions by said user are interpreted as a request for accessto at least some of said disabled features; creating an identifier forsaid operating context, wherein said identifier is created according toat least one measurable factor of said user's user environment; andusing said operating context identifier to associate said authorizationwith said user's operating context; whereby said authorization will notenable said disabled features when said at least one measurable factorhas changed beyond a pre-configured limit.
 4. The method of claim 1 inwhich said at least one measurable factor is selected from the set of:machine-readable user identifier serial number of user processor orproduct, machine-readable features of the user's system, user's voicepattern, spoken or typed password, processor time-stamp, nearly uniquetattoo, telephone number, network address, user's visual appearance, andbiological tissue samples.
 5. The method of claim 1 further comprisingthe steps of: ensuring that an authorization received for one or moreselected features for said unique user cannot be used for access byanother user or on another system; and permitting use of said at leastsome enabled features in a different operating context; whereby userscan obtain authorization to test or demonstrate said selected featureson one system and provide additional copies of the multimedia file toothers who must then request their own authorizations.
 6. A method forlimiting access to selected features of a data object, comprising thesteps of: compressing or encrypting portions of said data object;distributing said data object with at least some operable features;offering to decompress or decrypt one or more portions of said dataobject when a user of one of said operable features attempts to usefeatures of at least one of said compressed or encrypted portions;receiving a request from a user or user's system, said requestidentifying an operating context and said one or more compressed orencrypted portions; transmitting an authorization to said user or user'ssystem to decompress or decrypt at least one compressed or encryptedportion, where said authorization is uniquely associated with saidunique user; whereby said selected portion is decompressed or decryptedonly for said identified operating context.
 7. The method of claim 6further comprising the steps of: providing a user environment in whichpre-defined actions by said user are interpreted as a request for accessto at least some of said compressed or encrypted features; creating aunique identifier for identifying said operating context according to atleast one measurable factor of said user's user environment; and usingsaid unique identifier to associate said authorization with said user'suser environment; whereby said authorization will not enabledecompression or decryption of said compressed or encrypted portion whensaid at least one measurable factor has changed beyond a pre-configuredlimit.
 8. A method for limiting access to selected data features ofcopyable encoded information accessed by a user on a user's system, andfor restricting access to said selected data features to a particularoperating context, comprising the steps of: locking said selected datafeature, having a feature identifier, with a corresponding key;receiving an unlock request, from the user or user's system, saidrequest having a operating context identifier and a feature identifier;transforming said key using at least said unique operating contextidentifier to form an authorization; transmitting said authorization tosaid user or user's system; reverse transforming said authorizationusing said unique operating context identifier to obtain the keycorresponding to said feature identifier; and using said key totemporarily unlock said selected data feature; whereby saidauthorization can only be used to access the selected data feature inthe presence of said operating context identifier.
 9. The method ofclaim 8 in which said operating context identifier is generatedaccording to a pre-determined combination of values selected from theset of: measurable parameters of a user's system, measurable physicalinformation about the user, and information supplied by the user. 10.The method of claim 8 in which said operating context identifier isgenerated for each unlock request according to the present state of apre-determined combination of values collected by a user's system. 11.The method of claim 8 in which said feature identifier is generatedusing unique identification information about said selected data featurein combination with said operating context identifier.
 12. The method ofclaim 8 in which said transforming step uses encryption.
 13. The methodof claim 8 further comprising the steps of: retrieving an authorizationthat has been previously stored for said selected data feature; reversetransforming said retrieved authorization to obtain a valid key; andunlocking said feature with said valid key; whereby a selected datafeature once unlocked remains unlockable in the presence of saidpreviously stored authorization and said operating context underpre-determined conditions.
 14. The method of claim 8 further comprisingthe steps of: storing at least some of said authorizations received bysaid user or user's system; selecting a candidate authorizationpreviously stored for said selected data feature; validating saidselected candidate authorization with a reverse transform using saidunique operating context identifier; and either unlocking said selecteddata feature, if said selected candidate authorization is successfullyvalidated, or else signaling the user or user's system to obtain a validauthorization.
 15. The method of claim 8 wherein: said transforming stepis based upon a prime factorization of an N-digit number using saidoperating context identifier as a randomization key, where N is chosento be within the factorization capabilities of a licensing computer butbeyond the capabilities of the user or the user 's system, and saidreverse transforming step comprises generating the N-digit number insaid user's system, and confirming that said N-digit number is theproduct of the factorization contained in said authorization.
 16. Themethod of claim 8 in which said transforming step is based upon use ofthe operating context identifier as the seed for a complex pseudo-randomnumber generator, and said reverse transforming step confirms that theauthorization generated in the user's system corresponds to theauthorization received, based upon a transform of the operating contextidentifier and feature identifier.
 17. The method of claim 8 furthercomprising the step of: storing at least some of said authorizationsreceived by said user or user's system; determining whether a validauthorization is stored corresponding to a selected data feature desiredby said user using said operating context identifier; and advertisinginformation to said user regarding purchase of a new authorization forsaid selected data feature when said user's system determines that acorresponding authorization has not been stored or cannot be validatedin the present operating context.
 18. The method of claim 17 in whichsaid advertising information includes information selected from the setof: description of the selected data feature, advantages of the selecteddata feature, cost or other requirements for access to the selected datafeature, source identification for obtaining an authorization,identification of an owner or licensor of rights in the selected datafeature, and method of obtaining a valid authorization for access tosaid selected data feature.
 19. The method of claim 8 further comprisingthe steps of: permitting a user or user's system to operate or access atleast some unprotected features of said encoded information; assistingsaid user in selection of a selected data feature by disclosinginformation to said user regarding data features for which no validauthorization is present; and connecting said user's system to alicensing processor for transmission of said unlock request and forreception of said authorization.
 20. The method of claim 8 furthercomprising the steps of: said user indicating a desire for a selecteddata feature beyond any features already operable or already unlocked;informing the user that the feature is locked, where said feature islocked unless a valid authorization has been stored for said user-ID andsaid authorization is still valid; offering said user information aboutpossible benefits of obtaining access to said locked feature; offeringto said user to provide said user with access to said feature uponagreement with predetermined conditions; and forming an unlock requestfor a user who indicates agreement with said at least some of saidpredetermined conditions.
 21. The method of claim 8 in which saidselected data feature is selected from the following abilities: todecompress encoded information, to access a text file, to execute asoftware or hardware program, to access a further distribution channel,to decrypt digital data, to enable a high-quality output, to enablestorage of processing results, to access a digitized multimedia file, toenable predetermined hardware or software features of the user's system,and to access an analog playback process for an audio, video ormultimedia recording.
 22. The method of claim 8 in which said selecteddata features are locked by a transform of either encryption orcompression, or both, for which a key is required to reverse eachtransform; and a password or authorization provides access to said key;wherein access to each selected data feature requires a password orauthorization which is adequately unique to prevent different users oruser's systems from sharing passwords.
 23. The method of claim 8 inwhich at least some of said steps of locking, unlocking, transformingand reverse transforming are carried out in firmware in the user'ssystem.
 24. A method for sharing limited access to selected datafeatures of copyable encoded information stored on a server, and forpermitting only uniquely identified workstations to unlock said selecteddata features, comprising the steps of: locking said selected datafeature, having a feature-identifier, with a corresponding key;receiving an unlock request having a unique workstation-identifier and afeature identifier from the workstation; transforming said key using atleast said unique workstation identifier to form an authorization;transmitting said authorization to said workstation; reversetransforming said authorization using said unique workstation identifierto obtain the key corresponding to said feature-identifier; and usingsaid key to unlock said selected data feature; whereby said key can onlybe used to access the selected data feature from a uniqueworkstation-identifier.
 25. The method of claim 24 in whichauthorizations formed for a given workstation are then stored on theserver in workstation-specific locations.
 26. The method of claim 24 inwhich said unique workstation identifiers are constructed such that anyworkstation identified as being on the same network can use the sameauthorization for the selected data feature of the encoded information.